if you think just because the heads not ported the R2's wont do anything vs stock cams you're wrong 100%. i know for a fact thats not what Aaron was getting at, so you should be careful how you word things. you made it sound like you wouldn't see nothing unless the head was ported.

but i know what you're trying to say and what he was trying to get at i think.

with porting the head it will only increase the gains that much more then not porting, so he recommends porting. since the cams really effect low end and mid range then it makes perfect sense to me, because im pretty sure when you port the evo head properly you get ALOT more low end and mid range opened up. i dont think you see as much benefit at high RPM as you do low rpm after porting the evo head.

i have about 3 evos i think im doing with R2's so we will see. 2 of them are on stock non ported heads.

 

see how you worded your first post? "you WILL need headwork". you made it sound like without porting you will see nothing from these cams, which is definitely not true.

i'm just trying to correct what you said so others don't read it and think WTF? i can't get these cams because my heads not ported.

you would be surprised what people will take from the post you made! just be careful how you word stuff.

without porting the head you will not see max performance / potential from these cams <-- that is how you should have worded it.

 

Im not saying it wont make power, but if your not gonna port the head, your better off running a different cam, less lift but longer duration, who cares if the cam can lift valves 12mm when you have no extra air to take advantage of it. Thats all im saying

I think a lot of people "over cam" their set ups and dont pick the correct cam

 

Not one mention of dropping the valve guides down in the head for a high lift cam. My 4g63 runs the Kelford 294HL. I run 12.5 mm of lift and it is required to drop the valve guides down in the head.

This is also a very simple answer to the problem. A camshaft has a required/recommended open/closed spring pressure. Every cam shaft out there has different peak rate of velocity for the ramp rate in both direction(opening the valve/ closing the valve) so the numbers may be slightly different from one cam to the next. The Supertech duals have plenty of pressure on a properly setup head(proper installed height) to rev to 11k and have 12mm of lift from an off the shelf cam.

Also to say "this cam is better than this one because this guy tested it", is very vague. Damn near everyone has a different setup with different goals.

The actual difference between the R2 and the S2 is pretty obvious to see from their cam cards. It is easy to get caught up with the advertised number. It seems like everyone does it but the @.050 number is the most important. The advertised number compared to the @.050 number gives you an idea how fast the valve is opening. The piston velocity in a stroker setup allows a cylinder to fill more at low lift areas. GSC with their stroker cams are trying to take advantage of this but a normal 2.0L with a 1.7ish rod ratio will also pick up gains from this cam. A 4 valve in general has good cylinder filling at low lifts with rod ratios below 1.7.

R2-
6008R2 ADV Duration Duration @ 1mm Peak Lift CenterLine
Intake 274 236 12.10mm 107
Exhaust 274 236 11.90mm 115

S2-6008S2 ADV Duration Duration @ 1mm Peak Lift CenterLine
Intake 274 230 11.20mm 107
Exhaust 274 230 11.00mm 113

With them side by side it is quite obvious GSC made a BADASS cam with the R2. 6 more degrees @ .050 with the same advertised duration is just asking for more lift which it was given. That cam should act like a S2 at low rpms and make gobs more power above 5.5k


P.S. I do agree people don't take advantage of a properly ported head. But a camshaft will without a doubt make a difference on our stuff non ported.

 

thats exactly why i have some customers on 2L's testing these cams. its a cam thats in between a s2 and a s3. thanks for sharing your knowledge Jwhalen07.

I took pics of the GSC 5041 springs and retainers but my stupid website is not working. but im going to link it anyways for when it decides to work again.

I took pictures of the backside of the retainer for you Derek.

 

I posted the link to gsc tom. Its easy to see in their picture what I'm talking about. I'm hoping to get a back to back test vs. My BF cams since my car has the perfect setup for these cams.

On the ported head conversation I think its eaisest to think of it this way.... going from the s2 to r2 cams will have a bigger power increase with a ported head vs. A stocker. Since the ported head will flow a lot more at 12mm lift than the stock head.

 

Look at the flow increase from the br ported head vs. Stock. Way more flow at 12.5mm lift! IE .500"

https://secure.buschurracing.com/cat...products_id=39

 

Ya I think this cam would work better on a smaller turbo(let me edit.. Smaller hotside). Something stock frame or small t3 that has a higher than ideal back pressure. The low advertised helps get the overlap out of it to prevent reversion. It seems like they designed it around a 2.3/2.4 stroker running a T3 .68- .82 housing revving to 8-8400k rpm. An intake manifold and a properly designed header would net some impressive gains out of the rpm and airflow needed to get these in the sweet spot.

I might add that it is vital to set a head up correctly running these cams. My shop normally drops the guides before we port the head and before the valve job if the customer requests a large power number/ large cam. If this is not properly done you can experience a catastrophic failure.

 

Speaking of which, who offers good ported heads?

Is the GSC Power Division CNC Head any good? Does anyone run it?

 

Can i ask this, My set up is a 2.3 4g64 crank, curt brown ported intake, curt brown head, soon to be r2 cams, curt brown ported exhaust manifold, ported fp black, j fab or toxic fab 02 dump.
Would be close to an ideal set up with these cams in regards to good match for each other? (street car that see's a little 1/4 and a bit of track racing)

Thank You
Shane

 

I realize you are trying to protect your livelihood here since you are an online tuner, but please do not attempt to discredit my statements in your own self interest. My info is not skewed at all.

I had genuine Supertech dual valve springs, purchased via STM. STM installed them, not once, but twice. Both times, the springs un-seated the valve stem seals, causing me to leak oil. Seen here: https://www.evolutionm.net/forums/ev...s-leaking.html

The first set WAS returned to Supertech and a new set installed. Same issue.

So unless you want to officially say that STM did not install them correctly, STM sold me 2 sets of knock-off springs/valve sets, or that STM skewed the info, then please reconsider your statement.

 

FWIW: I have a set of supertech behives & my head is dis-assembled.

I will post my retainer to stem seal clearance tonight. iirc, they have some crazy coil bind #, but that doesnt mean sqwat if the retainer is kissing the seal.

0.460" int.

0.452" exh

i will locate the pn's of the actual pieces later.

I think i am using oem seals.

I have the supertech seals sitting in their bags, maybe i will measure them & see if there is a difference from the inside shoulder to the top of the seal compared to the oem seals.

 

You have a hell of a setup. Those cams should be a great combo for that displacement and mods. Rev the thing out to 8-8500 and if the tune it good and boost holds it should have a flat torque curve.

I am also surprised that more of the Evo owners don't use the Kiggly line up of springs. There springs have been spintron tested and tested at the track to handle 12k rpm and over .500 lift. They are SUPER light and work extremely well.

 

They are stating the range from install to coil bind not seal to bottom of the retainer. Pretty much no one states retainer to seal because of the differences in guide height, valve keeper groves on both the valve and the keeper, the angle at which the valve seal is cut, and what type of seal is used. Don't forget those seals arent exactly nominal held tolerance so they could move a round a bit.

As far as clearance goes on the 4G63 you can't make a retainer that uses the factory keeper and run the factory guide at spec'd height and have more than 12.7mm of clearance. at least that is what we got on our setup measured with a CMM.


Thanks for Sharing your findings OP.

Greg

 

FWIW, ForcedPerformance has already been down this road. FPX cams years ago had similar lift and advertised duration rates. They had ALL KINDS of problems and I think eventually stopped selling them because the average user didn't listen to what they were saying and simply tossed them in with standard "dual valvesprings" and without checking clearances.

To start with, when you open the valve this much, you run into geometry issues that can lead to high valvetrain component wear rates. Then you have seal to retainer clearance issues. Then piston to valve clearance issues. Aaron went over all this in his original thread. I asked a simple question of basically "if the best case scenario where everything in the head is right, can these work with stock pistons." His response was basically, "if you check the clearances it will be VERY CLOSE."

Somehow that statement turned into "this will work in a stock motor" because people don't understand jack **** about building motors.